The title screen tells us that we are going to flashback to thirteen days ago, which is going to translate to about four months of our time, and half a season ago episode-wise. Locke's mounting the guns in the armory, and Michael comes in to whisper that he wants a gun for target practice. Locke asks if it's supposed to be a secret (because of the whispering), and Michael says that Jack's asleep. Locke agreeably asks him if he's going for more target practice, which Michael fidgetingly accepts as a good cover story, and he checks his watch. "Got a date?" asks Locke, and Michael shrugs something about old habits. Locke hands him over a rifle, and Michael "accidentally" spills bullets all over the floor. Locke crouches down to pick them up, and Michael bonks him with the butt end of the rifle, although it doesn't actually come close to hitting Locke. Maybe he hit the air hard enough, and the air was what knocked Locke out? That would also explain Locke's slightly delayed reaction in crumpling in a heap on the floor.
Michael briefly looks remorseful, and then goes racing into the computer room, where he starts hammering on the keyboard. The cursor doesn't even respond for a second, and when the screen finally displays what Michael types, it's all gibberish, like "asajsskadfjklsdjfl," like in his distress he can't lift his fingers from the home keys, so I hope he's gotten used to communicating with Walt using only those letters. "Dad sad; has flak; a salad." D'oh! He deletes all that, and types, "You okay?" Fool! "OK" would save valuable Walt-rescuing time. Seconds go by, with no response. Michael looks crushed. Then: "ok. no time. come soon?" Look, Walt. That's not how we do things at TWoP. Proper capitalization, dude. I don't care that you've been "kidnapped by the Others" or whatever the fuck, I'm bumping up your warning level. Michael types that he's coming NOW, and also, "You said north?" like AS IF Walt knows from directions. Michael types "north WHERE?" because probably by this time Walt has also worked out latitude and longitude. There's a long wait, and then, on the screen, "when they take me out, there's huge rocks with a big HOLE in the middle by the beach. you'll know when you see it." Michael types, "It's gonna be okay. I'm coming, Walt." And he says out loud, "I'm coming, Walt," as he types it, too.
Then we hear Jack call Locke's name from somewhere else in the bunker, and Michael grabs the gun and goes and shoves it in Jack's face as Jack finds the unconscious Locke in the armory, and yells about going after his son, which is "a father's right," and we skip the bit about Michael threatening to shoot the computer, and Michael slams the door of the armory.